# How are bats affected by wind turbines?

Dead bats are found beneath wind turbines all over the world. It’s estimated that tens to hundreds of thousands die at wind turbines each year in North America alone.

Unfortunately, it’s not yet clear why this is happening. It’s possible that wind turbines interfere with seasonal migration and mating patterns in some species of bats. More than three quarters of the bat fatalities at wind turbines are from species known as “tree bats,” which tend to migrate long distances and roost in trees. These bats migrate and mate primarily during late summer and early autumn, which is also when the vast majority of bat fatalities at wind turbines occur. It’s also possible that bats mistake slow or stopped turbine blades for trees.

Learn more at the USGS North American Bat Monitoring Program (NABat) website.

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